Posts Made By: Alex McConahay

All right, every year about this time we say--Are we Astromarters going to get together this year at RTMC and see what we look like in person? And every year nobody shows where we suggest. And then afterwards, every year, a bunch of people ask--So where were you?--

So, like, is anybody going to suggest it this year?.....(I'm not. I hate rejection! It reminds me too much of asking for dates in college.)

The program is on the RTMC website, if anybody wants to pick a time and a place.

Alex

Ok, so, tell me what you know about solar projection viewing.

I'm trying to set up a solar viewing system. I have a couple of refractors which are ideal. I also have a couple of white-light filters.

If I use one of the white light filters, there is not enough light to project.

What happens if I take the filter off? Seems to me that the light rays will pass right on through and "project" the image onto a white reflective surface about a foot or two away.

Is there a problem with that? Will it generate too much heat as the light is passing through? Will I fry an eyepiece? or what?

Alex

I've been taking astrophotos with my TV85 for some time, and decided to move on to my Meade 10 inch F4.5 newt to gather more light and get more focal length.

I knew coma would be an issue, but intended to use my Para-corr on the scope.

Mine is an older Para-Corr (I.e, not a "tunable" ParaCorr). It has a two inch barrel that fits into the focuser drawtube and holds the optics. At the other end of that is a set of t-ring threads that screw accept a two inch barrel that receives the camera adapter, camera, etc.

Now, visually (using an eyepiece), this Para-Corr reduces the coma just as I would expect. However, I have no idea what it was doing this weekend when I attached the camera. I had horrible coma trying to focus the stars with DSLR focus. I rechecked collimation, looked for possible bright spots to flare (and look like coma) and all the regular things I could think of.

Anybody have any idea what is happening here?

Alex

The launch window for the Delta rocket from Vandenberg is set for 20:14 tonight. These are always spectacular at dusk/sunset, so get out and watch. Hope it is clear for you--I have clouds.

Oh, and take some equipment so we won't be off topic.

Alex

I'm just about finished working my way through Scott Ireland's relatively new book (with sample photos on CD) on Photoshop Astronomy. It is quite a rewarding experience.

He takes one through numerous tutorials on Curves, Historgram stretching, star shaping, masking, stacking, color correcting, reducing noise, sharpening, and customizing for various types of output.

I am fairly familiar with Photoshop, but much of what I did before was based on trial and error--what I thought looked good. After the tutorials, I now know some of the theory behind the process. For instance, I have been told (or read) many times what the parameters of unsharp masking meant. But I have never really been able to tell what numbers to use for the various settings. Now that I have seen how Ireland determines the settings, I know how to figure that out.

The experience continued one tradition--every time I sit with somebody or read something on Photoshop I get a few "I did not know it did that!!!" shots. This book is chock full of them, and I have used Photoshop a lot.

All in all, this book was a pretty good investment...

Alex

Why does anything need to be deleted??--well, except for a few things in a few forums where I never go......

Alex

Nightfall is a different kind of star party. Instead of camping in the old tent, Nightfall is held at a fancy resort, with nice rooms, a couple of pools, a restaurant, and all that. It is being held this year in late October in Anza Borrego, California. Anza Borrego is known for its very dark skies and beautiful daytime scenery. And this one weekend a year, they turn off all the lights (or put in red lights).

Last I checked there were a few rooms (and more than a few RV spots) left at the resort for Nightfall.

Also this year, Mike Unsold, who is the author of Images Plus astro-imaging software, will be giving a series of free and paid workshops.

For more information see

http://www.rtmcastronomyexpo.org/nightfall.htm

Alex

Hi all,

I guess I have missed Herb saying that the feedback and rating systems are for completed transactions only. And I did not see it in any the "Terms of Service" when I read through real quick just now.

I agree it is Herb's Forum, and can comply with whatever he says.

But, does it not seem that if we had a really bad experience with somebody we kinda should rate that somebody accordingly (not meanly, not vindictively, not nasty, just according to our side of the story as factual as we can make it)?

And we should be able to do this even though we did not go through with the transaction. Otherwise, the rating system is only for successful transactions. And what good is that? How does it let others know about people who are flaky?

And if we can only talk about done deals, why do we get a notice when we respond to an ad (not when the deal is done) that says we may rate the other person?

Alex

Why is my St-4 reporting good tracking, when it is not, apparently, focusing on a star?

Here is the situation.

In several of my astrophotographs I have very short star trails, even though my autoguider (ST-4) reports everything was okeedokee. So, I assumed that I had some kind of slippage between the separate guidescope and the Newt, or slippage in the mirror/secondary.

I always take a dark frame before actually going to Find and Focus and starting a track.

Last night, I was tracking on Triangulum galaxy, and had goods tracking (can't wait to process!!!!).......Then I moved the scope over to M1 to start on that. Got it all set up and focused, and did a Find and Focus on the ST-4 to see if I had a guidestar. Luckily, I did, right about where I needed it (39-48 for those of you who use St-4. It had a brightness of about 27 units if I recall correctly.). I did not bother to take a dark frame, since I had not reset anything in the exposure menu. I had finished with M33, hit Interrupt, moved to M1, and after focusing, etc, hit find and focus.. When I got a usable guidestar result immediately, I simply retrained. My retraining result was good, and so I started the tracking and the exposures. The exposures showed tracking errors (stars slightly elongated which were not there in M33) even though the St-4 was reporting tracking errors of random from +4 to -4--and usually about in the 2-3 range or less--in other words, pretty good tracking from what I am use to. I continued the exposure despite the small tracking errors. I should be able to process them out--and it was 3:00 am.

After an hour (12 x 5 minutes with a DSLR). I forgot to turn the ST-4 off, but moved the scope as I was getting ready to put the scope away. Usually when one does this, the ST-4 squawks because it has lost the guide star. But mine did not do complain at all. It continued to report happily---- tracking errors of one to four units, sometimes less, even though I was turning the scope wherever I wanted. Obviously, it was not reporting on actual results.

What gets me--if It was just reporting a hot pixel, would it not report no tracking errors at all? Why did it track M33 Okay, but have a problem with M1?

Why was I getting a report of good tracking, when it was not, apparently, focusing on a star at all?

Alex

As some of you may know, Mike Unsold, developer of Images Plus software, will be in Southern California at the Nightfall Star Party in Borrego Springs October 19-22. He will be presenting an all day workshop on Saturday the 21st, and will be there the whole weekend for visiting and working with the Astro-imagers.

As of today, about two-thirds the seats for the Unsold Workshop have been sold. I have heard some people may be thinking of waiting until the conference itself to register. Some or all of those last minute people may be disappointed. The rooms in the hotel were all spoken
for last I checked, although I understand they plan to develop a waiting list at the Palm Canyon Resort. Also, of course, there are RV spots at the Palm Canyon, and other hotels in town (as well as the state park) for those who do not yet have a place to stay.

Information about Nightfall itself is at

http://www.rtmcastronomyexpo.org/nightfall.htm

If you want to register for the Unsold presentation, go to:

http://www.rivastro.org/ras_images_plus_reg.html

Mike has prepared two CD's of sample images for us to work through, and this promises to be quite an informative hands-on workshop. But I'm also excited about spending the evenings imaging with Mike puttering around the telescope field. I've got a few questions to ask.

Alex